Case 138

A 76 year old male with elevated PSA and here is the prostate core biopsy:

What's your interpretation without PIN4 IHC? A: Adenocarcinoma, 3+3

B: Atypical small acinar proliferation (ASAP)

C: Benign glands

Answer

All the screenshot focus are adenocarcinomas Gleason score 3+3. In this case, the amphophilic, clear, or pale granular cytoplasm and taller cells with clear to pale pink cytoplasm with basal nuclei are worrisome.

Gleason Pattern 3 – Diagnostic features

Architectural Features

• Well-formed, individual small glands with lumina

• Glands are discrete but infiltrate haphazardly among benign glands

• Small caliber and crowded glandular structures

• Sharp, rigid luminal borders

  
  

Cytological Features

• Enlarged nuclei with mild variation in size

• Prominently enlarged and/or multiple nucleoli

• Nucleoli often located at the nuclear periphery

• Tinctorial (staining) differences from adjacent benign glands

  
  

Intraluminal Features

• Well-defined lumina with distinct cytoplasmic staining

• Lack of secretions typical of benign glands

  
  

Basal Cell Layer

• Complete absence of basal cells (key for malignancy)

• Confirmed by immunohistochemistry (e.g., p63, HMWCK negative)

  
  

Additional Diagnostic Clues

• Crowding and irregular arrangement of malignant glands

• Infiltrative growth pattern among benign prostatic tissue

• Positive for AMACR (alpha-methylacyl-CoA racemase) in malignant glands

Case credit: UCSD Pathology

Author: Wangpan Jackson Shi, MD

Reference: https://app.expertpath.com/document/acinar-adenocarcinoma/98b02f2c-96bd-45c6-af12-b691043ce362?term=prostate%20adenocarcinoma&searchType=documents&category=All&documentTypeFilters=all